Whether you sport an “innie” or “outtie” is determined at infancy. “Before birth, the umbilical cord is attached to the baby,” says plastic surgeon Dr. Bruce Nadler of New York. “After the baby is born, the cord shrivels up and you get an innie. If the cord has an extra blood supply, it stays alive and heals itself over the stomach to create an outtie.” Though innies are more common, there are no medical benefits or probs with either. But, believe it or not, there’s a cosmetic procedure to make your outtie an innie.